The choice of mask patterns is key to the performance of the system as it defines the resolving capability of the system and the applicability of the reconstruction algorithm. The field of ghost imaging has seen an evolution in both experimental setups and algorithms [1]}, [2]}. Although the vast majority of computational ghost imaging and the related work on single pixel cameras use a spatial modulator positioned in the image plane of the object, the original work by Shapiro [3]} recognised that this need not be the case. Rather, given any specific modulation, the resulting form of the light field in the plane of the object could be calculated using numerical beam propagation techniques enabling both lens free and far field implementations [4]}.
